Old vines are wonderful for the intensity and richness their grapes bring to Graham’s ports, but sadly there comes a point when the yields are so low, and there are so many falhas (missing vines) that an old vineyard is just not economically viable any more. Then it is more important to invest for the future, re-plant the vineyard and start again. So it was at Quinta do Tua this year, when we made the decision to clear some old mixed vineyards. Ironically, during last year’s harvest, we commented that these old vines were adjacent to some of our newest vines, a plantation of Souzão.
So, how exactly is a new vineyard created from an old one? First, the old posts and wires are cleared out and the old vines as well. Then the whole hillside – in this case 5 hectares – gets broken up and smoothed out.
Once the whole area is pretty well smoothed out, the next step is to establish the main roadways through the vineyard. This is critical – not only are the roads used for transport, they are the key to our drainage strategy. All the terraces will be gently inclined so that accumulated surface water will run off into the roadways and then follow the roads down the hill, thus minimising erosion damage to the terraces. In some cases, we may cut a dedicated drainage ditch alongside the roadway, and even lay down pipes if appropriate.
The day I visited this plantation, the roadways had been established, and we were sculpting the patamares, the terraces atop earth banks which are used on all gradients greater than 30% incline.
The process looks deceptively simple. The bulldozer starts at the top of the vineyard and effectively snowploughs the first terrace and the angled talude (embankment) above it, allowing all excess rock and soil to cascade down the hill. They then repeat this manoeuvre over and over, moving down the hill one terrace at a time. The real art of it, however, is to always angle the terrace surface back towards the hill side, and generally sculpt the length of the terrace to angle ever so gently downwards towards the roadway end, so runoff is managed into the drainage system established earlier.
We use an excavator (giratória) to dig a succession of ditches and move the soil from each new ditch to fill in the last one, turning over the top layer of soil. This surriba breaks up the schist, but if we hit huge outcrops of solid rock which the diggers can’t manage, we might have recourse to compressors and dynamite. It’s really the same process as double digging your vegetable patch, but on a slightly bigger scale!
Finally our own tractorista, Alexandre, trundles along the new patamar with a little mini dozer pulling a scarifier to smooth out the tilth of the (still pretty rocky) soil.
Sometime between January and March of next year these 5 hectares will be planted in single varietal blocks of bench-grafted Touriga Nacional and Touriga Francesa. Although we will allow the vines to sprawl their first year, we do need to get the trellis system set up some time before July in order to comply with the regulations governing the subsidies for vineyard replanting.